TECHNICAL FIELD
[0001] The present disclosure relates to dental impression trays.
BACKGROUND ART
[0002] In general, a silicone impression material, an alginate impression material, or the
like is used to take an intraoral impression when making prostheses in dental treatment.
In this case, an impression tray is used to intraorally insert and hold the impression
material (refer to Patent Document 1, for example). That is, the impression material
is placed on the impression tray which is inserted into a patient's oral cavity, and
an intraoral shape is transferred to the impression material by pressing the impression
material against the patient's oral cavity. After the impression material hardens,
the impression tray, in a state integrally holding the impression material transferred
with the intraoral shape, is removed from the oral cavity.
[0003] When taking the impression in this manner, it is necessary to take the impression
of an alveolar ridge having a smooth curve in the case of an edentulous patient (including
an almost edentulous patient). In this case, the impression material must be pressed
against the alveolar ridge with a uniform force, thus requiring a very high skill.
For this reason, the impression is often taken two times with respect to the edentulous
patient, due to need to more accurately take the intraoral impression.
[0004] More particularly, a ready-made impression tray is used to take a first impression
of the alveolar ridge, and an edentulous model is thereafter made from the hardened
impression. An "individual tray", which is an impression tray exclusively for the
edentulous patient, is made from the edentulous model. Next, a thin layer of impression
material is placed on the individual tray to take a second impression of the alveolar
ridge, and the second impression is used to make an accurate edentulous model.
PRIOR ART DOCUMENTS
PATENT DOCUMENTS
[0005] Patent Document 1: International Publication Pamphlet No.
WO 2015/022805
DISCLOSURE OF THE INVENTION
PROBLEM TO BE SOLVED BY THE INVENTION
[0006] The difficulty of taking the impression is high for the edentulous patient when compared
to a dentulous patient, because the impression is taken from a site which is extensive,
including not only hard tissues but also soft tissues. More particularly, there is
a soft tissue called a retromolar triangle (retromolar pad) behind a last molar of
mandible. For this reason, when a conventional impression tray such as that described
in Patent Document 1 is used, for example, an excessively high impression pressure
applied to the retromolar, or an insufficient impression (insufficient spreading of
the impression material), may easily occur.
[0007] Hence, there also is an impression tray having a shape in which the retromolar pad
portion is removed in advance (for example, a Frame Cut Back tray (manufactured by
YDM Corporation)). However, if the impression tray does not include a portion opposing
the retromolar pad, the accuracy of the impression may deteriorate because it is not
possible to take the impression of the retromolar pad.
[0008] Accordingly, one object of the present disclosure is to provide a dental impression
tray which can take an accurate impression.
MEANS OF SOLVING THE PROBLEM
[0009] A dental impression tray according to one aspect of embodiments of the present invention
includes a tray body on which an impression material is placed when taking an impression;
and an impression pressure adjusting part provided on at least one end of the tray
body along a direction of a dental arch, and capable of adjusting an impression pressure,
wherein the impression pressure adjusting part is provided at a position opposing
a retromolar pad when taking the impression, and is capable of adjusting the impression
pressure by removing at least a portion from a rearmost portion thereof.
EFFECTS OF THE INVENTION
[0010] According to the present disclosure, it is possible to provide a dental impression
tray which can take an accurate impression.
BRIEF DESCRIPTION OF DRAWINGS
[0011]
FIG. 1 is an assembled perspective view of a mandibular impression tray according
to one embodiment.
FIG. 2 is an exploded perspective view of the mandibular impression tray illustrated
in FIG. 1.
FIG. 3 is a perspective view of a tray body illustrated in FIG. 2 viewed from a mandibular
side.
FIG. 4 is a plan view of the mandibular impression tray viewed from the maxillary
side.
FIG. 5 is a plan view of the mandibular impression tray viewed from the mandibular
side.
FIG. 6 is a schematic diagram for explaining a range of an impression pressure adjusting
part.
FIG. 7A is a diagram illustrating an example of a first stage of a removal pattern
of the impression pressure adjusting part.
FIG. 7B is a diagram illustrating an example of a second stage of the removal pattern
of the impression pressure adjusting part.
FIG. 7C is a diagram illustrating an example of a third stage of the removal pattern
of the impression pressure adjusting part.
FIG. 8 is a schematic diagram for explaining a position of a retromolar pad in an
oral cavity.
MODE OF CARRYING OUT THE INVENTION
[0012] Hereinafter, embodiments will be described with reference to the accompanying drawings.
In order to facilitate the understanding of the description, the same constituent
elements in each of the drawings are designated by the same reference numerals as
much as possible, and a repeated description of the same constituent elements will
be omitted.
[0013] In the following description, an x direction, a y direction, and a z direction are
mutually perpendicular directions. The x and y directions are approximately horizontal
directions, and the z direction is an approximately vertical direction. The x direction
is a front-and-rear direction when a mandibular impression tray 1 (dental impression
tray) is placed in an oral cavity, a positive x direction is a lip side, and a negative
x direction is a throat side. The y direction is a leftand-right direction when the
mandibular impression tray 1 is placed in the oral cavity, a positive y direction
is a left side of a dental arch, and a negative y direction is a right side of the
dental arch. The z direction is an up-and-down direction when the mandibular impression
tray 1 is placed in the oral cavity, a positive z direction is a maxillary side, and
a negative z direction is a mandibular side.
[0014] FIG. 1 is an assembled perspective view of the mandibular impression tray 1 according
to one embodiment. FIG. 2 is an exploded perspective view of the mandibular impression
tray 1 illustrated in FIG. 1. FIG. 3 is a perspective view of a tray body 2 illustrated
in FIG. 2 viewed from the mandibular side. FIG. 4 is a plan view of the mandibular
impression tray 1 viewed from the maxillary side. FIG. 5 is a plan view illustrating
the mandibular impression tray 1 viewed from the mandibular side.
[0015] The mandibular impression tray 1 is an example of a dental impression tray, and is
an instrument which holds an impression material for taking a mandibular impression
in the oral cavity. The mandibular impression tray 1 illustrated in FIG. 1 is for
an edentulous patient. As illustrated in FIG. 1 and FIG. 2, the mandibular impression
tray 1 includes a tray body 2, and a handle 3. The impression which is taken is used
to make a mandibular prostheses. For example, a silicone impression material or an
alginate impression material is used as the impression material. The tray body 2 and
the handle 3 are formed of a resin material (plastic), such as polyacetal, polycarbonate,
or the like, for example
[0016] The tray body 2 is a component on which the impression material is placed when taking
the impression. From a viewpoint of reducing an amount of the impression material
used, the tray body 2 according to this embodiment is formed to have a configuration
including an outer peripheral shape and concavo-convexes, simulating a general shape
of the oral cavity excluding a tongue portion at a mandible, as illustrated in FIG.
1 through FIG. 5. That is, the outer peripheral shape of the tray body 2 is a curved
shape simulating a dental arch shape, protruding in the positive x direction (lip
side), and a central portion surrounded by this arch shape is an air space because
the central portion corresponds to the tongue portion. The concavo-convex shape of
the tray body 2 is formed so as to protrude in the positive z direction (maxillary
side), similar to a mandibular alveolar ridge, that is, so that a cross sectional
shape viewed from a direction of the dental arch becomes an arch shape protruding
toward the maxillary side.
[0017] The shape of the tray body 2 illustrated in FIG. 1 through FIG. 5 is merely an example,
and the shape employed in a known mandibular impression tray may be applied.
[0018] The tray body 2 is formed to the shape described above having approximately the same
thickness, and has an impression material filling surface 2A which is a concave curved
surface facing the negative z direction side as illustrated in FIG. 1 through FIG.
3 and FIG. 5, and a maxillary opposing surface 2B which is a convex curved surface
facing the positive z direction side as illustrated in FIG. 1 through FIG. 4. The
impression material placed on the impression material filling surface 2A when taking
the impression. The maxillary opposing surface 2B is mounted to face the maxillary
side when taking the impression.
[0019] As illustrated in FIG. 1 through FIG. 5, the tray body 2 is provided with a plurality
of through holes 8 and 9 penetrating the tray body 2 in a plate thickness direction
thereof, between the impression material filling surface 2A and the maxillary opposing
surface 2B, to allow the impression material to flow therethrough when the impression
material is pressed and deformed. The through holes 8 and 9 preferably have a diameter
of approximately 1 mm to approximately 5 mm. In addition, as illustrated in FIG. 3
and FIG. 5, the tray body 2 is provided with spacers 10 projecting in the negative
z direction from the impression material filling surface 2A, and the spacers 10 are
configured to prevent the tray body 2 from making close contact with the alveolar
ridge when taking the impression.
[0020] The configuration of the tray body 2 will be described in more detail. The tray body
2 has an anterior teeth part 4 disposed at an arch shaped central portion, a pair
of premolar parts 5 adjacent on both sides of the anterior teeth part 4 along the
y direction, and a pair of molar parts 6 adjacent to the throat side (negative x direction)
from the premolar parts 5. The anterior teeth part 4, the premolar parts 5, and the
molar parts 6 are disposed to oppose the anterior teeth part, the premolar parts,
and the molar parts of the mandible, respectively, when the tray body 2 is placed
on the mandibular alveolar ridge. Because this embodiment relates to the tray for
the edentulous patient, as illustrated in FIG. 3, an inner wall 2C on a central side
(tongue side) of the arch shape of the tray body 2 in the direction of the dental
arch, is formed to extend longer toward the mandibular side (negative z direction)
than an outer wall 2D on the outside. In addition, the inner wall 2C is formed so
as to extend from the anterior teeth part 4, longer towards the premolar parts 5 and
the molar parts 6.
[0021] The handle 3 applies an external force on the tray body 2 when taking the impression,
to generate an impression pressure. The handle 3 is detachably attached to the maxillary
opposing surface 2B of the anterior teeth part 4 of the tray body 2, as illustrated
in FIG. 1 and FIG. 2, for example.
[0022] The handle 3 has an engaging portion 3A extending in the z direction side to engage/disengage
with the anterior teeth part 4, and a holding portion 3B which bends approximately
at a right angle from the engaging portion 3A toward the positive x direction side
and extends in the positive x direction side.
[0023] A protrusion 4A protruding in the positive z direction is provided on the maxillary
opposing surface 2B of the anterior teeth part 4, at an approximate center position
along the y direction, and a pair of engaging holes 4B are provided on both sides
of the protrusion 4A along the y direction. On the other hand, a cavity portion 3C
to which the protrusion 4A fits, and engaging claws 3D disposed on both sides of the
cavity portion 3C along the y direction, are provided at an end of the engaging portion
3A of the handle 3 on the negative z direction side, and the engaging claws 3D are
inserted into and engage with the pair of engaging holes 4B. The handle 3 is attached
to the tray body 2 by causing the engaging portion 3A to approach the anterior teeth
part 4 from the positive z direction side, so that the cavity portion 3C is fitted
with the protrusion 4A, and the engaging claws 3D are inserted into and engage with
the engaging hole 4B.
[0024] In a state where the engaging portion 3A is engaged to the tray body 2, an operator
can apply an external force to the holding portion 3B toward the negative z direction
side, and transmit this external force to the tray body 2 via a coupling portion thereof
with the engaging portion 3A. As a result of the external force transmitted to the
tray body 2, the impression pressure is applied to the impression material and the
alveolar ridge. Here, the "impression pressure" refers to a pressure applied to an
alveolar ridge mucosa when the impression material is placed and the impression tray
is pressed against the alveolar ridge.
[0025] The handle 3 simply needs to be detachable with respect to the tray body 2, and an
engaging structure between the handle 3 and the tray body 2, and the shape of the
holding portion 3B of the handle 3, may be other than those of the examples of the
configurations illustrated in FIG. 2 or the like.
[0026] Preferably, the plurality of through holes 8 and 9 are provided so that center axes
thereof are aligned in the same direction. More particularly, the direction of the
center axes of the plurality of through holes 8 and 9 are more preferably a pressure
applying direction (z direction) with respect to the tray body 2 when taking the impression.
According to this configuration, the impression material is allowed to more easily
flow through the through holes 8 and 9 when applying the pressure to take the impression,
and it is possible to prevent the impression pressure from becoming excessively high.
In addition, the manufacturing is facilitated by aligning the through holes 8 and
9 in the same direction.
[0027] In particular, in this embodiment, a pair of impression pressure adjusting parts
7 which are capable of adjusting the impression pressure is provided at both ends
along the direction of the dental arch of the tray body 2, that is, on the negative
x direction side of the pair of molar parts 6. The impression pressure adjusting part
7 is provided at a position opposing the retromolar pad (position on the throat side
of the molar) when taking the impression, and is capable of adjusting the impression
pressure by cutting and removing at least a portion from a rearmost portion thereof.
The impression pressure adjusting part 7 can be cut using a dental handpiece or the
like, for example.
[0028] FIG. 8 is a schematic diagram for explaining the position of the retromolar pad in
the oral cavity. As illustrated in FIG. 8, the retromolar pad is a nodular soft tissue
region located at a position on the throat side (negative x direction side) of the
molars of the alveolar ridge. In the conventional impression trays described in Patent
Document 1 or the like, the trays are often formed to a position covering the region
of the retromolar pad.
[0029] Properties of the retromolar pad, such as a degree of inclination from the molars
to the maxilla, a protruding amount, softness, or the like illustrated in FIG. 8,
vary for each patient due to individual differences. For this reason, in conventional
impression tray, if the retromolar pad protrudes greatly toward the maxillary side,
for example, the end of the tray on the throat side may press the retromolar pad too
strongly when taking the impression, thereby applying an excessively high impression
pressure on the retromolar pad. On the contrary, if the retromolar pad does not protrude
greatly toward the maxillary side, the end of the tray on the throat side may not
be able to sufficiently press the retromolar pad when taking the impression, thereby
resulting in an inadequate impression (insufficient spreading of the impression material).
Hence, in the conventional impression tray, it may not be possible to take the impression
with a desired impression pressure, depending on the differences in the properties
of the retromolar pad.
[0030] In order to avoid the accuracy of the impression from deteriorating due to the properties
of the retromolar pad, there are existing impression trays having the retromolar pad
removed in advance (for example, Frame Cut Back tray (manufactured by YDM Corporation)).
However, if the impression tray does not have a portion opposing the retromolar pad,
the accuracy of the impression may deteriorate because it is not possible to take
the impression of the retromolar pad.
[0031] In addition, the conventional impression trays are limited to a product of the type
that covers the entire retromolar pad, or a product of the type having the shape with
the retromolar pad removed in advance, and a dentist had to choose the tray to be
used between the two types. Because the shape of the tray body is not uniform for
each of the types, the dentist had to tolerate a variation in the impression which
can be taken when using different types of impression trays.
[0032] With respect to these conventional problems, the impression tray 1 according to this
embodiment includes the impression pressure adjusting part 7 capable of adjusting
the impression pressure, by cutting and removing at least a portion from a rearmost
portion thereof as described above. Accordingly, the impression pressure is adjustable
by cutting the impression pressure adjusting part 7 according to the properties of
the patient's retromolar pad, and the impression of the retromolar pad can be taken
with the desired impression pressure, thereby enabling the impression to be taken
with a high accuracy.
[0033] Moreover, by removing the impression pressure adjusting part 7, the impression pressure
can be adjusted while maintaining the shapes of the other parts of the tray body 2
(anterior teeth part 4, the premolar part 5, and the molar part 6) to the same shape.
For this reason, unlike the conventional case where different types of impression
trays need to be used depending on the properties of the retromolar pad, a single
product can produce individual trays to suit multiple patients, and it is possible
to improve the convenience of the dentist.
[0034] A partition line 11 is provided on the tray body 2 at a boundary position between
a region where molars are originally present at a rearmost portion of the dental arch
and the retromolar pad when taking the impression, and the impression pressure adjusting
part 7 is provided on an inner side (negative x direction side) of the partition line
11. According to this configuration, a range of the impression pressure adjusting
part 7 can be clearly indicated to the dentist, to provide an indicator of the extent
to which the impression pressure adjusting part 7 can be cut when performing an impression
pressure adjusting operation, which is particularly effective with respect to an unskilled
dentist.
[0035] In this embodiment, the partition line 11 is formed as a convex line protruding from
the maxillary opposing surface 2B, however, the partition line 11 need only be visible
on the maxillary opposing surface 2B, and the partition line 11 may be other than
the convex line. For example, the partition line 11 may be formed as a concave line
which caves in from the maxillary opposing surface 2B, or as a printed line printed
on the maxillary opposing surface 2B. In addition, the type of line is not limited
to a solid line, and may be a dashed line, a series of round dots, or the like.
[0036] FIG. 6 is a schematic view for explaining the range of the impression pressure adjusting
part 7. FIG. 6 schematically illustrates the shape of a part of the tray body 2, corresponding
to the impression pressure adjusting part 7 on the negative y direction side, viewed
from even more the rear side (negative x direction side) of this part. As illustrated
in FIG. 1 or the like, the range of the impression pressure adjusting part 7 along
the x direction is more on the rear side than a boundary with the molar part 6. The
range of the impression pressure adjusting part 7 along the z direction is more on
the upper side than an intermediate position of the inner wall 2C of the tray body
2, as illustrated in FIG. 1 through FIG. 3, and FIG. 6. This intermediate position
will be described in more detail. As illustrated in FIG. 6, the intermediate position
is where the maxillary opposing surface 2B is inclined by a predetermined angle α
with respect to the vertical direction, from the lower end of the inner wall 2C of
the tray body 2. That is, the region of the impression pressure adjusting part 7 in
the view long the x direction may be represented as a range in which the maxillary
opposing surface 2B is inclined by the predetermined angle α (for example, 30 degrees)
or more in the negative y direction with respect to the z axis.
[0037] Further, the impression pressure adjusting part 7 is formed to have a porosity per
unit area higher than other parts (the anterior teeth part 4, the premolar part 5,
and the molar part 6) of the tray body 2, that is, so that it is possible to reduce
the effort required to cut the impression pressure adjusting part 7 and facilitate
a cutting operation.
[0038] More particularly, by providing the plurality of through holes 9, the impression
pressure adjusting part 7 has a higher porosity per unit area than the other parts
of the tray body 2. As illustrated in FIG. 1 through FIG. 5, the area of the impression
pressure adjusting part 7 defined by the partition line 11 is smaller than the area
of the other parts (the anterior teeth part 4, the premolar part 5, and the molar
part 6) of the tray body 2. On the other hand, the number of through holes 9 provided
in the impression pressure adjusting part 7 is the same as the number of through holes
8 provided in the other parts of the tray body 2 (three through holes each are illustrated
the examples of FIG. 1 through FIG. 5). As a result, the porosity of the impression
pressure adjusting part 7 becomes high, and the cutting of the impression pressure
adjusting part 7 is facilitated by this configuration.
[0039] Moreover, the through holes 9 provided in the impression pressure adjusting part
7 are disposed along the partition line 11. According to this configuration, the cutting
of the impression pressure adjusting part 7 along the partition line 11 can further
be facilitated, and the adjustment of the impression pressure in multiple stages can
be facilitated. This will further be described with reference to FIG. 7A through FIG.
7C.
[0040] FIG. 7A through FIG. 7C illustrate examples of the first through third stages of
a removal pattern of the impression pressure adjusting part 7. For the sake of convenience,
among the three through holes 9 provided in the impression pressure adjusting part
7, a through hole 9A is located on the most negative z direction side, a through hole
9B is located on the most negative y direction side, and a through hole 9C is located
on the most positive x direction side. That is, the through hole 9A, the through hole
9C, and the through hole 9B are disposed in this order along the partition line 11
from the rear side.
[0041] When cutting and removing the impression pressure adjusting part 7, a portion of
the rearmost end of the impression pressure adjusting part 7 is first removed by cutting
along the through hole 9A in the first stage of the removal pattern, as illustrated
in FIG. 7A. Next, the entire rear end of the impression pressure adjusting part 7
is then removed by cutting along the through hole 9B in addition to the through hole
9A in the second stage of the removal pattern, as illustrated in FIG. 7B. Further,
the entire impression pressure adjusting part 7 is removed by cutting along the through
hole 9C in the third stage of the removal pattern, as illustrated in FIG. 7C.
[0042] Accordingly, by disposing the plurality of through holes 9A, 9B, and 9C along the
partition line 11, the portions of the through holes 9A, 9B, and 9C need not be cut
when cutting the impression pressure adjusting part 7 along the partition line 11,
thereby making it even easier to remove the impression pressure adjusting part 7.
In addition, if the cutting progresses along the through holes 9A, 9B, and 9C, the
impression pressure adjusting part 7 can be removed in multiple stages as illustrated
in FIG. 7A through FIG. 7C, and the adjustment of the impression pressure in multiple
stages can be facilitated.
[0043] This embodiment was described with reference to the specific examples. However, the
present disclosure is not limited to these specific examples. The specific examples
added with design modifications by those skilled in the art, as appropriate, also
fall within the scope of the present disclosure as long as the examples include the
features of the present disclosure. Each of the elements included in each of the specific
examples described above, and the arrangement, conditions, shape, or the like of each
of the elements, are not limited to those of the examples, and may be modified, as
appropriate. Each of the elements included in each of the specific examples may vary
in combination, as appropriate, unless a technical contradiction is introduced by
the combination.
[0044] In the embodiment described above, the mandibular impression tray 1 for the edentulous
patient is illustrated as the dental impression tray according to the embodiment,
however, a mandibular impression tray for a patient having several remaining teeth
may be used as the dental impression tray according to the embodiment.
[0045] In the embodiment described above, the illustrated impression pressure adjusting
part 7 is configured to include the plurality of through holes 9, however, other configurations
may be employed as long as the porosity per unit area of the impression pressure adjusting
part 7 can be set high. For example, the through holes 9 may have a polygonal shape
instead of a circular shape as illustrated in the drawings, or have a configuration
obtained by subjecting the impression pressure adjusting part 7 to a slitting process
or a meshing process.
[0046] Similarly, although the configuration illustrated in the embodiment described above
is provided with the plurality of through holes 9 in the impression pressure adjusting
part 7, other configurations may be employed as long as the impression pressure adjusting
part 7 can be cut easily. For example, the configuration may include the impression
pressure adjusting part 7 having a thickness smaller than thickness of other parts
of the tray body 2. In addition, the number of through holes 9 provided in the impression
pressure adjusting part 7 may be other than three.
[0047] Although the configuration illustrated in the embodiment described above is provided
with the partition line 11 between the molar part 6 and the impression pressure adjusting
part 7 of the tray body 2, the partition line 11 need not be provided in the configuration
if the range of the impression adjusting part 7 is clear due to configurations, such
as the configuration which increases the porosity per unit area of the impression
pressure adjusting part 7, the configuration which facilitates the cutting of the
impression pressure adjusting part 7, or the like.
[0048] The configuration illustrated in the embodiment described above is provided with
the impression pressure adjusting part 7 on both ends along the direction of the dental
arch of the tray body 2, however, the impression pressure adjusting part 7 may be
provided on only one of the two ends along the direction of the dental arch of the
tray body 2.
[0049] The configuration illustrated in the embodiment described above adjusts the impression
pressure by cutting and removing at least a portion of the rearmost portion of the
impression pressure adjusting part 7, however, the method of removing the impression
pressure adjusting part 7 may be other than cutting, such as a method of folding and
breaking the ends to disconnect the ends, or the like, for example.
DESCRIPTION OF THE REFERENCE NUMERALS
[0051]
- 1
- Mandibular impression tray (dental impression tray)
- 2
- Tray body
- 2A
- Impression material filling surface
- 2B
- Maxillary opposing surface
- 2C
- Inner wall
- 2D
- Outer wall
- 3
- Handle
- 4
- Anterior teeth part
- 5
- Premolar parts
- 6
- Molar parts
- 7
- Impression pressure adjusting parts
- 8, 9
- Through holes
- 10
- Spacer
- 11
- Partition line
1. A dental impression tray comprising:
a tray body on which an impression material is placed when taking an impression; and
an impression pressure adjusting part provided on at least one end of the tray body
along a direction of a dental arch, and capable of adjusting an impression pressure,
wherein the impression pressure adjusting part is provided at a position opposing
a retromolar pad when taking the impression, and is capable of adjusting the impression
pressure by removing at least a portion from a rearmost portion thereof.
2. The dental impression tray as claimed in claim 1, wherein the impression pressure
adjusting part is formed to have a porosity higher than other parts of the tray body.
3. The dental impression tray as claimed in claim 1, wherein the impression pressure
adjusting part is formed to have a thickness smaller than other parts of the tray
body.
4. The dental impression tray as claimed in claim 1, wherein a partition line is provided
on the tray body at a boundary position between a region where molars are originally
present at a rearmost portion of the dental arch and the retromolar pad when taking
the impression, and the impression pressure adjusting part is provided on an inner
side of the partition line.
5. The dental impression tray as claimed in claim 1, wherein the impression pressure
adjusting part is provided with a plurality of through holes, thereby having porosity
higher than other parts of the tray body.
6. The dental impression tray as claimed in claim 5, wherein the plurality of through
holes is provided so that center axes thereof are aligned in the same direction.
7. The dental impression tray as claimed in claim 6, wherein the direction in which the
center axes of the plurality of through holes are aligned is a pressure applying direction
with respect to the tray body when taking the impression.
8. The dental impression tray as claimed in claim 5, wherein the plurality of through
holes is disposed along a partition line provided at a boundary position between the
impression pressure adjusting part and the other parts of the tray body.
9. The dental impression tray as claimed in
claim 1, wherein the tray body is for edentulous mandibular use.
10. The dental impression tray as claimed in claim 1, comprising:
a handle detachably attached to the tray body, and applying an external force to the
tray body when taking the impression, to generate the impression pressure.